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<title>lwres_getnameinfo</title>
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<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="refentry" lang="en">
<a name="id2476275"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2>Name</h2>
<p>lwres_getnameinfo &#8212; lightweight resolver socket address structure to hostname and
      service name
    </p>
</div>
<div class="refsynopsisdiv">
<h2>Synopsis</h2>
<div class="funcsynopsis">
<pre class="funcsynopsisinfo">#include &lt;lwres/netdb.h&gt;</pre>
<table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
<tr>
<td><code class="funcdef">
int
<b class="fsfunc">lwres_getnameinfo</b>(</code></td>
<td>const struct sockaddr *�</td>
<td>
<var class="pdparam">sa</var>, </td>
</tr>
<tr>
<td>�</td>
<td>size_t �</td>
<td>
<var class="pdparam">salen</var>, </td>
</tr>
<tr>
<td>�</td>
<td>char *�</td>
<td>
<var class="pdparam">host</var>, </td>
</tr>
<tr>
<td>�</td>
<td>size_t �</td>
<td>
<var class="pdparam">hostlen</var>, </td>
</tr>
<tr>
<td>�</td>
<td>char *�</td>
<td>
<var class="pdparam">serv</var>, </td>
</tr>
<tr>
<td>�</td>
<td>size_t �</td>
<td>
<var class="pdparam">servlen</var>, </td>
</tr>
<tr>
<td>�</td>
<td>int �</td>
<td>
<var class="pdparam">flags</var><code>)</code>;</td>
</tr>
</table>
</div>
</div>
<div class="refsect1" lang="en">
<a name="id2543393"></a><h2>DESCRIPTION</h2>
<p>
       This function is equivalent to the
      <span class="citerefentry"><span class="refentrytitle">getnameinfo</span>(3)</span> function defined in RFC2133.
      <code class="function">lwres_getnameinfo()</code> returns the
      hostname for the
      <span class="type">struct sockaddr</span> <em class="parameter"><code>sa</code></em> which
      is
      <em class="parameter"><code>salen</code></em> bytes long.  The hostname is of
      length
      <em class="parameter"><code>hostlen</code></em> and is returned via
      <em class="parameter"><code>*host.</code></em> The maximum length of the
      hostname is
      1025 bytes: <code class="constant">NI_MAXHOST</code>.
    </p>
<p> The name of the service associated with the port number in
      <em class="parameter"><code>sa</code></em> is returned in <em class="parameter"><code>*serv.</code></em>
      It is <em class="parameter"><code>servlen</code></em> bytes long.  The
      maximum length
      of the service name is <code class="constant">NI_MAXSERV</code> - 32
      bytes.
    </p>
<p>
       The <em class="parameter"><code>flags</code></em> argument sets the
      following
      bits:
      </p>
<div class="variablelist"><dl>
<dt><span class="term"><code class="constant">NI_NOFQDN</code></span></dt>
<dd><p>
              A fully qualified domain name is not required for local hosts.
              The local part of the fully qualified domain name is returned
              instead.
            </p></dd>
<dt><span class="term"><code class="constant">NI_NUMERICHOST</code></span></dt>
<dd><p>
              Return the address in numeric form, as if calling inet_ntop(),
              instead of a host name.
            </p></dd>
<dt><span class="term"><code class="constant">NI_NAMEREQD</code></span></dt>
<dd><p>
              A name is required. If the hostname cannot be found in the DNS
              and
              this flag is set, a non-zero error code is returned.
              If the hostname is not found and the flag is not set, the
              address is returned in numeric form.
            </p></dd>
<dt><span class="term"><code class="constant">NI_NUMERICSERV</code></span></dt>
<dd><p>
              The service name is returned as a digit string representing the
              port number.
            </p></dd>
<dt><span class="term"><code class="constant">NI_DGRAM</code></span></dt>
<dd><p>
              Specifies that the service being looked up is a datagram
              service,  and causes getservbyport() to be called with a second
              argument of "udp" instead of its default of "tcp".  This is
              required
              for the few ports (512-514) that have different services for UDP
              and
              TCP.
            </p></dd>
</dl></div>
<p>
    </p>
</div>
<div class="refsect1" lang="en">
<a name="id2543534"></a><h2>RETURN VALUES</h2>
<p><code class="function">lwres_getnameinfo()</code>
      returns 0 on success or a non-zero error code if an error occurs.
    </p>
</div>
<div class="refsect1" lang="en">
<a name="id2543546"></a><h2>SEE ALSO</h2>
<p><span class="citerefentry"><span class="refentrytitle">RFC2133</span></span>,
      <span class="citerefentry"><span class="refentrytitle">getservbyport</span>(3)</span>,
      <span class="citerefentry"><span class="refentrytitle">lwres</span>(3)</span>,
      <span class="citerefentry"><span class="refentrytitle">lwres_getnameinfo</span>(3)</span>,
      <span class="citerefentry"><span class="refentrytitle">lwres_getnamebyaddr</span>(3)</span>.
      <span class="citerefentry"><span class="refentrytitle">lwres_net_ntop</span>(3)</span>.
    </p>
</div>
<div class="refsect1" lang="en">
<a name="id2543604"></a><h2>BUGS</h2>
<p>
      RFC2133 fails to define what the nonzero return values of
      <span class="citerefentry"><span class="refentrytitle">getnameinfo</span>(3)</span>
      are.
    </p>
</div>
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